Indian Standard EPOXY RESIN FOR PAINTS -- SPECIFICATION ICS 87.060.01 0 BIS 2001 BUREAU MANAK OF BHAVAN, 9 INDIAN BAHADUR DELHI 110002 STANDARDS SHAH ZAFAR MARG NEW Price (lroop 4 Raw Materials for Paint Industry Sectional Committee, CHD 21 FOREWORD This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Raw Materials for Paint Industry Sectional Committee had been approved by the Chemical Division Council. Epoxy resin is one of the most important resins used by paint industries in high performance paint application. It may be corrosion resistance or chemical resistance coating. The need has been felt for preparation of this standard because of excessive usage of epoxy resins in paint formulation. There is no 1S0 standard and its equivalent available on the subject. The composition of the technical committee responsible for formulating this standard is given in Annex B. For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2:1960 `Rules for rounding off numerical values ( revised )'. The number of significant places retained in the rounded off value should be the same as that of specified value in this standard. IS 14925:2001 Indian Standard EPOXY RESIN FOR PAINTS -- SPECIFICATION 1 SCOPE 1.1 This Indian Standard prescribes the requirement and methods of sampling and test for epoxy resin used in paint industry. 2 REFERENCES 2.1 The Indian Standards listed below contain provisions which through reference in. this text, constitute provision of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards. 1S No. shall have differentmolecular weight or epoxy equivalent weight depending on stochiometric ratios of above mentioned reactants. The manufacturer shall declare molecular distribution and average molecular weight. 4.2 Depending upon the applications in paint system epoxy resins can be classified into three types based on average molecular weight or epoxy equivalent weight when determined through the method specified in Annex A, alongwith physical state of resin. Physical State Type A Type B Grade 1 Grade 2 Type C Grade 1 Grade 2 5 REQUIREMENTS 5.1 Epoxy resin shall comply with the requirements specified in Table 1. 5.2 Keeping Quality The material when stored in normal storage condition at the ambient temperature shall retain its property for atleast 12 months from the date of manufacture as prescribed in Table 1. 6 FORM OF SUPPLY 6.1 Epoxy resin shall supply as 100 percent solids or any other percentage solution in any suitable solvent as agreed to between the manufacturer and the purchaser. 7 PACKING AND MARKING 7.1 Packing The material shall be packed in sound, clean WI dry containers as agreed to between the manu filc[urcr WI the purchaser. High molecular weight, solid 2900 3750 1700-2300 2400-3500 Liquid Low molecular weight, solid 900 1400 425-550 850-1000 Average Molecular Weight 360-380 Epoxy Equivalent Weight 180-200 Title Methods of sampling and test for resins for paints: methods ( second 354 (Part l): 1987 General test revision ) (Part4): 1303:1983 6667:1972 1070:1992 1986 Special test methods for epoxy resins ( second revision ) Glossary of terms relating to paints ( second revision) Glossary of terms used in synthetic resin industry Specification for reagent grade water (third revision ) 3 TERMINOLOGY 3.1 For the purpose of this standard definitions given in IS 354 ( Part 1 ), IS 1303, IS 6667 and the following shall apply. 3.2 Ambient Temperature It is a temperature between 21 "C and 38"C. 3.3 Epoxide Equivalent The mass of an epoxide compound, in grams, which contains one mole ofepoxide group. 4 CLASSIFICATION 4.1 A condensation product of epichlorohydrin and bispheneol A in alkaline condition, which leads to formation of epoxy group containing resins. These resins 1 1S 14925:2001 Table 1 Requirement for Epoxy Resins ( Clauses 5.1 and5.2 ) sl No. (1) Characteristics Type A Type B Grade 1 Grade 2 Type C Grade 1 Grade 2 Method of Test, Rcf to Annex (8) Cl No. of (9) IS (2) Colour ( on `Gardner' (3) scale ), 3 (4) 4 (5) 4 (6) 4 (7) 6-- i) Max ii) 6.2 of Is 354 ( Part 1 ) Viscosity a) As such at 25° * 0.05°C ( Cps ) b) 40 percent in butyl carbitol at 25 + 0.5°C ( cps ) c) 50 Percent in 1 : 1 mixture of O. Xylene/D.A.A. at 25 + 0.5°C ( cps ) 800015000 -- -- -- -- -- -- 80-170 470-750 1 600-34004000-1 I 000 8.1 or 8.4 of 1s 354 ( Part I ) -- 100-150 -- -- -- iii) Softening ring ) point ( ball and -- 60-70°C 90- IOO"C 117-127°C 130-145°C 10.1 of Is 354 ( Part I ) A 6 of IS 354 ( Part 4 ) 7 Ofls 354 [ Part I ) iv) v) vi) Epoxide equivalent Hydrolyzable content by mass, g/nYole chlorine 180-200 0.5 425-550 0.2 850- I 000 I 700-2300 0.2 0.2 2400-3 0.2 500 Max -- -- -- -- Relaive density (at '27 q 2"C) 1.15-1.20 7.2 Marking The containers shall be marked with the following information: a) b) c) d) e) t) Name and type of the material; Type and grade; Mass of the material; Month and year of manufacturer; Batch No. or lot No. in code or otherwise; and Name of the manufacturer recognized trade-mark. and/or any 7.2.1.1 The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Aet, 1986 and the Rules and Regulations made thereunder. The details of conditions under which the licence for the use of the Standard Mark may be granted to manufacturers or producers maybe obtained from the Bureau of Indian Standards. 8 QUALITY OF REAGENTS 8.1 Unless specified otherwise pure chemicals and distilled water (IS 1070 ) shall be used. NOTE-- `Pure chemicals' shall r,,ean chemical that do not contain impurity which affect the results of the analysis. 7.2.1 BIS Certl~cation Marking The product may also be marked with the Standard Mark. 9 SAMPLING 9.1 Representativesamples of the material shall be drawn as prescribed in 3 of IS 354 ( Part 1 ). 2 IS 14925:2001 ANNEX A [ Clause 4.2 and Table 1, S1 No. (iv) ] "METHOD OF DETERMINATION OF EPOXIDE EQUIVALENT OF EPOXY COMPOUNDS A-1 PRINCIPLE A-1.1 Method A Epoxide groups react with nascent hydrogen bromide produced by the action of a standard 0.1 mol/1solution of perchioric acid on tetraethylammonium bromide. The end-point is determined either by using crystal violet as indicator or, for dark-coloured products, by a potentiometric method. This method is recommended for normal reactive epoxy resin. A-1.2 Method B standard perchloric acid solution, is given by the formula: ~= where m = is the mass ( in g ) of potassium hydrogen phthalate, and V= is the volume ( in ml ) of perchloric acid used in the titration. NOTES m VX0.20422 The amino nitrogen of the epoxyamine is titrated with a standard solution of perchloric acid. The value thus obtained is used as a correction in the calculation of the epoxide equivalent as obtained in Method A. This method is recommended for slow reactive epoxy resin. NOTE -- Safety goggles and safety screen maybe used while carrying out tests through the above methods. 1 If a potentiometric method is used, it is necessary to standardize the perchloric acid in the same way as used for the test. 2 The use of a correction factor is necessary if the temperature of the perchloric acid at the time of its standardization is different from that at the time of the test. This is because of the significant coefficient of expansion of the standard perchloric acid solution ( 1.07 x 103 `C-l ), which corresponds to a volume variation of 0.1 percent "C. A-2 REAGENTS A-2.1 Acetic Acid, Glacial -- Conform ingto 1S625. A-2.2 Acetic Anhydride A-2.3 Suitable Solvent for Solution of the Sample-- for example chloroform, dibutyl phthalate, chlorobenzene. A-2.4 Potassium Hydrogen Phthalate -- Dry the potassium hydrogen phthalate for 2 h at 120"C before use. A-2.5 Crystal Violet, Indicator Solution -- Dissolve 100 mg of crystal violet in 100 ml of acetic acid. Perchloric Acid, 0.1 mol/1 Standard Solution -- To 8.5 ml ofa 70 percent (m/m) aqueous A-2.7 Tetraethylammonium Bromide Reagent Solution ­ Dissolve 100 g of tetraethylammonium bromide in 400 ml of acetic acid. Add a few drops of the crystal violet indicator solution; if it changes colour, bring it back to the original colour with the perchloric acid standard solution. NOTE -- For some epoxy compounds of low reactivity, the use of tetrabutylammonium iodide is advised, either as the solid or as a 10 percent solution in chloroform; in this case, light should be excluded as much as possible. Solutions of tetrabutyl ammonium iodide in chloroform are unstable and should be freshly prepared for each titration. A-2.6 A-3 APPARATUS A-3.1 Balance -- Accurate to within 0,1 mg. A-3.2 Conical Flask -- 100 ml or 200 ml, with ground glass neck and ground glass stopper. A-3.3 Micro-burette -- Of capacity 10 ml. solution of perchloric acid, add 300 ml of acetic acid followed by 20 ml of acetic anhydride. Dilute to 1 Iitre with acetic acid and mix thoroughly, Standardize this solution by titrating it against 200 mg of potassium hydrogen phthalate dissolved in 50 ml of acetic acid, using the crystal violet indicator solution ( see Note 1 ). Use 4 to 6 drops of the crystal violet indicator solution and continue the titration until a stable green colour is obtained. Note the temperature, r~,of the solution of perch loric acid at the time of standardization ( see Note 2 ). The concentration, C, in mol/1 of the 3 A-3.4 Magnetic Stirrer ethylene-coated bar. -- With polytetrafluor- A-3.5 Thermometer--Calibrated to permittemperature measurements to within= 0.1 `C. A-3.6 Pipette, One-mark, Conforming to IS I 117. 10 ml Capacity -- In addition the following apparatus is rcquirtd if a IS 14925:2001 potentiometric end-point is to be used. A-3.7 pH-millivoltmeter compensating type. -- Preferably by the formula: of the 1 000x m EE= (V, -vo)(l :;;; )Xc A-3.8 Glass and Calomel Reference Electrodes-- The electrode system shall have a salt bridge of lithium chloride in glacial acetic acid. If the electrodes are not in constant use, wash the glass electrode with butanone, rinse with water, soak the electrode for at least 10 min in a solution of dilute hydrochloric acid ( 9 ml of hydrochloric acid made up to 100 ml with water ) and rinse again with water and butanone. If the electrodes are in constant use, it is sufficient to soak the electrodes in water between carrying out tests. A-4 PROCEDURE A-4.1 Method A where m = is the mass ( in g ) of the test sample; VO = is the volume ( in ml ) of the standard perchloric acid solution used in the blank test; V, = is the volume ( in ml ) of the standard perchloric acid solution used in the test on the sample; t = is the temperature ( in 0C ) of the standard perchloric acid solution at the time of tests; perchloric acid solution at the time of standardization; and C = isthe concentration( in mol/1) of the perchloric acid solution at the time of standardization. The result is sometimes expressed as epoxide index ( in moles of epoxide groups per kg ) calculated as follows: Epoxide index= -- EE A-5.2 Method B 1000 [, = is the temperature ( in `C ) of the standard Weigh into the flask, to the nearest 0.2 mg, a quantity of samplecontainingfrom0.6 millimolesto 0.9 millimoles of epoxide groups. ( This corresponds to a mass of between 0.6 x EE mg and 0.9 x EE mg, where EE is the epoxide equivalent of the epoxide compound. ) Add 10 ml of the solvent chosen for solution of the sample; then dissolve the sample by stirring and, if necessary, heat slightly. Cool the solution to room temperature. Add 20 ml of the acetic acid and, with the pipette, 10 ml of the tetraethylammonium bromide reagent. Then add 4 to 6 drops of the crystal violet indicator solution. Titrate with the standard perchloric acid solution immediately, in a closed system while stirring the contents of the flask'by means of the magnetic stirrer. Continue the titration until a stable green colour is obtained. Note the temperature, r, of the standard perchloric acid solution. At the same time carry out a blank test, omitting the sample. If a potentiometric end point is used, carry out the above procedure using the electrodes and omitting the indicator solution. Take the mid-point of the inflection on the titration curve as the end point. A-4.2 Method B Follow the procedure for Method A, including the blank test. Also carry out a second test with the sample, but without the addition of the tetraethylammonium bromide reagent. A-5 EXPRESSION OF RESULTS A-5.1 Method A The epoxide equivalent, EE, in grams per mole, is given 4 The epoxide equivalent, EE, in grams per mole, is given by the formula: EE = where tn = is the mass ( in g ) of the test sample; ml = is the mass ( in g ) of the test sample used in the second test, that is, without the add ition of the tetraethylammonium bromide reagent; VO = is the volume ( in ml ) of the standard perchloric acid solution used in the blank test; VI = is the volume ( in ml ) of the standard perchloric acid solution used in the first test on the sample; V2 = is the volume ( in ml ) of the standard perchloric acid solution used in the second test on the sample, that is, without the addition of the tetraethylammonium bromide reagent; t 1000xm (V, -VO-V2 +(1m, &o)xc ­1 s = is the temperature ( in "C ) of the standard IS 14925:2001 perch loric acid solution at the time of the tesls; is the temperature perchloric acid standardization; is tk conccnlmtion (in `C) solution and (in nlol/1) of the perchloric of the standard at the time of A-6 TEST REPORT The test report shall include the following particulars : a) A complete identification of the material tested, including type, source, manufacturer's code numbers etc; b) c) The epoxide equivalent; The solvent used for solutiol] and the reagent used ifit is not tetraetllylalllllloll itllll bromide: Whether a visual or potentiometric end-point was used; and Any other factor likely to have affected the result. acid solution The result is sometimes at the time of standardization. expressed as epoxide index, expressed in moles of epoxide groups per kilogram, caicutated as follows: Epoxide index= I 000 -- EE d) e) IS 14925:2001 ANNEX B ( F'OrewOrd ) COMMITTEE COMPOSITION Raw Materials for Paint Industry Sectional Committee, CHD 21 Chairman D~ R. B. TIROOKAR Members SHRI R. SIUNIVASAN SHRI E. RAMANATIiAN ( Alternate SHRI K. P. JAMISOTHAR SHtu S. G. SHI:TYE( Alfernafe SHRI B. P. MALIK SHIU N. K. RAY ( AJrernme ) DR L. K. ACiAI